from __future__ import annotations

import argparse
import ast
import functools
import logging
import os
import sys
from collections import defaultdict
from typing import Any
from typing import Callable
from typing import DefaultDict
from typing import Dict
from typing import List
from typing import Optional
from typing import Tuple
from typing import TypeVar

import unicorn as U
from typing_extensions import ParamSpec

import pwndbg
import pwndbg.aglib.arch
import pwndbg.aglib.disasm.disassembly
import pwndbg.aglib.nearpc
import pwndbg.aglib.qemu
import pwndbg.aglib.regs
import pwndbg.aglib.symbol
import pwndbg.arguments
import pwndbg.chain
import pwndbg.color
import pwndbg.color.context as C
import pwndbg.color.memory as M
import pwndbg.color.syntax_highlight as H
import pwndbg.commands
import pwndbg.commands.telescope
import pwndbg.integration
import pwndbg.ui
from pwndbg.aglib.arch import get_thumb_mode_string
from pwndbg.color import ColorConfig
from pwndbg.color import ColorParamSpec
from pwndbg.color import message
from pwndbg.color import theme
from pwndbg.commands import CommandCategory

if pwndbg.dbg.is_gdblib_available():
    import gdb

    import pwndbg.gdblib.ptmalloc2_tracking
    import pwndbg.gdblib.symbol
    import pwndbg.ghidra

log = logging.getLogger(__name__)

T = TypeVar("T")
P = ParamSpec("P")

theme.add_param("backtrace-prefix", "►", "prefix for current backtrace label")

# TODO: Should namespace be "context.backtrace"?
c = ColorConfig(
    "backtrace",
    [
        ColorParamSpec("prefix", "none", "color for prefix of current backtrace label"),
        ColorParamSpec("address", "none", "color for backtrace (address)"),
        ColorParamSpec("symbol", "none", "color for backtrace (symbol)"),
        ColorParamSpec("frame-label", "none", "color for backtrace (frame label)"),
    ],
)


def clear_screen(out=sys.stdout) -> None:
    """
    Clear the screen by moving the cursor to top-left corner and
    clearing the content. Different terminals may act differently
    """
    ## The ANSI escape codes we use here are described e.g. on:
    # https://en.wikipedia.org/wiki/ANSI_escape_code#CSIsection
    #
    ## To sum up the escape codes used below:
    # \x1b - Escape | Starts all the escape sequences
    # [ - Control Sequence Introducer | Starts most of the useful sequences
    # H - Cursor Position | Moves the cursor to row n, column m (default=1)
    # \x1b - Escape | Starts all the escape sequences
    # <n> J - Erase in Display | Clears part of the screen.
    # If n is 0 (or missing), clear from cursor to end of screen.
    # If n is 1, clear from cursor to beginning of the screen.
    # If n is 2, clear entire screen (and moves cursor to upper left on DOS ANSI.SYS).
    # If n is 3, clear entire screen and delete all lines saved in the
    # scrollback buffer (this feature was added for xterm and is supported
    # by other terminal applications
    out.write("\x1b[H\x1b[2J")


config_reserve_lines = pwndbg.config.add_param(
    "context-reserve-lines",
    "if-ctx-fits",
    "when to reserve lines after the prompt to reduce context shake",
    help_docstring="""
The "if-ctx-fits" setting only reserves lines if the whole context would still fit vertically in the current terminal window.
It doesn't take into account line-wrapping due to insufficient terminal width.
""",  # TODO: maybe it could take into account line-wrapping?
    param_class=pwndbg.lib.config.PARAM_ENUM,
    enum_sequence=["never", "if-ctx-fits", "always"],
)


def reserve_lines_maybe(cmd_lines: int) -> None:
    """
    Scroll the terminal up a few lines to reduce shaking
    when repeatedly printing the context.

    Only do this if the context would still fit on
    the screen.
    """
    if config_reserve_lines == "never":
        return

    # If we are clearing the screen, we already have the maximum number of empty
    # lines below us, no need to scroll.
    if config_reserve_lines == "if-ctx-fits" and config_clear_screen:
        return

    # Could use .get_cmd_window_size() but lldb doesn't provide it
    rows, _ = pwndbg.ui.get_window_size(sys.stdout)
    leftover_lines = rows - cmd_lines
    # Take away one line for the prompt (e.g. pwndbg>) which is printed after the context
    leftover_lines -= 1

    # Need one line for the newline generated by pressing enter
    needed_empty = 1
    # Also need to cover extra lines that are printed before we start calculating/printing
    # the context.
    # Even though they are cleared when config_clear_screen=True, they still
    # cause shake, so we still account for them.
    needed_empty += pwndbg.dbg.pre_ctx_lines

    if not config_clear_screen:
        # Since we are not clearing the screen, we assume the prompt is at the bottom
        # of the window
        if config_reserve_lines == "always" or leftover_lines >= needed_empty:
            # We always write to stdout since that is where the prompt will be
            # ANSII codes
            # \x1b[#S  scroll the terminal up by # lines
            # \x1b[#A  move the cursor up by # lines
            sys.stdout.write(f"\x1b[{needed_empty}S\x1b[{needed_empty}A")
    else:
        assert config_reserve_lines == "always"
        # Since we are clearing the screen, leftover_lines describes actual empty lines.
        leftover_lines = max(leftover_lines, 0)
        if leftover_lines < needed_empty:
            to_scroll = needed_empty - leftover_lines
            sys.stdout.write(f"\x1b[{to_scroll}S\x1b[{to_scroll}A")


config_clear_screen = pwndbg.config.add_param(
    "context-clear-screen", False, "whether to clear the screen before printing the context"
)
config_output = pwndbg.config.add_param(
    "context-output", "stdout", 'where Pwndbg should output ("stdout" or file/tty)'
)
config_context_sections = pwndbg.config.add_param(
    "context-sections",
    "regs disasm code ghidra stack backtrace expressions threads heap_tracker",
    "which context sections are displayed (controls order)",
)
config_max_threads_display = pwndbg.config.add_param(
    "context-max-threads",
    4,
    "maximum number of threads displayed by the context command",
)

# Storing output configuration per section
outputs: Dict[str, str] = {}
output_settings: DefaultDict[str, Dict[str, Any]] = defaultdict(dict)


@pwndbg.config.trigger(config_context_sections)
def validate_context_sections() -> None:
    valid_values = [
        context.__name__.replace("context_", "") for context in context_sections.values()
    ]

    # If someone tries to set an empty string, we let to do that informing about possible values
    # (so that it is possible to have no context at all)
    if not config_context_sections.value or config_context_sections.value.lower() in (
        "''",
        '""',
        "none",
        "empty",
        "-",
    ):
        config_context_sections.value = ""
        print(
            message.warn(
                f"Sections set to be empty. FYI valid values are: {', '.join(valid_values)}"
            )
        )
        return

    for section in config_context_sections.split():
        if section not in valid_values:
            print(
                message.warn(f"Invalid section: {section}, valid values: {', '.join(valid_values)}")
            )
            print(message.warn("(setting none of them like '' will make sections not appear)"))
            config_context_sections.revert_default()
            return


class StdOutput:
    """A context manager wrapper to give stdout"""

    def __enter__(self):
        return sys.stdout

    def __exit__(self, *args, **kwargs) -> None:
        pass

    def __hash__(self):
        return hash(sys.stdout)

    def __eq__(self, other) -> bool:
        return isinstance(other, StdOutput)


class FileOutput:
    """A context manager wrapper to reopen files on enter"""

    def __init__(self, *args) -> None:
        self.args = args
        self.handle = None

    def __enter__(self):
        self.handle = open(*self.args)
        return self.handle

    def __exit__(self, *args, **kwargs) -> None:
        self.handle.close()

    def __hash__(self):
        return hash(self.args)

    def __eq__(self, other):
        return self.args == other.args


class CallOutput:
    """A context manager which calls a function on write"""

    def __init__(self, func) -> None:
        self.func = func

    def __enter__(self):
        return self

    def __exit__(self, *args, **kwargs) -> None:
        pass

    def __hash__(self):
        return hash(self.func)

    def __eq__(self, other):
        return self.func == other.func

    def write(self, data) -> None:
        self.func(data)

    def writelines(self, lines_iterable) -> None:
        self.func("".join(lines_iterable))

    def flush(self):
        try:
            return self.func.flush()
        except AttributeError:
            pass

    def isatty(self):
        try:
            return self.func.isatty()
        except AttributeError:
            return False


def output(section: str):
    """Creates a context manager corresponding to configured context output"""
    target = outputs.get(section, str(config_output))
    if not target or target == "stdout":
        return StdOutput()
    elif callable(target):
        return CallOutput(target)
    else:
        return FileOutput(target, "w")


parser = argparse.ArgumentParser(description="Sets the output of a context section.")
parser.add_argument(
    "section",
    type=str,
    help="The section which is to be configured. ('regs', 'disasm', 'code', 'stack', 'backtrace', 'ghidra', 'args', 'threads', 'heap_tracker', 'expressions', and/or 'last_signal')",
)
parser.add_argument("path", type=str, help="The path to which the output is written")
parser.add_argument("clearing", type=bool, help="Indicates whether to clear the output")
banner_arg = parser.add_argument(
    "banner",
    type=str,
    nargs="?",
    default="both",
    help="Where a banner should be placed: both, top , bottom, none",
)
parser.add_argument(
    "width",
    type=int,
    nargs="?",
    default=None,
    help="Sets a fixed width (used for banner). Set to None for auto",
)


@pwndbg.commands.Command(parser, aliases=["ctx-out"], category=CommandCategory.CONTEXT)
def contextoutput(section, path, clearing, banner="both", width: int = None):
    if not banner:  # synonym for splitmind backwards compatibility
        banner = "none"
    elif banner not in ("both", "top", "bottom", "none"):
        raise argparse.ArgumentError(banner_arg, f"banner can not be '{banner}'")

    outputs[section] = path
    output_settings[section].update(
        {
            "clearing": clearing,
            "width": width,
            "banner_top": banner in ("both", "top"),
            "banner_bottom": banner in ("both", "bottom"),
        }
    )


def resetcontextoutput(section):
    target = outputs.pop(section, None)
    if target:
        # Remove all settings except for the ones that are not related to output redirection
        output_settings[section] = {
            k: v
            for k, v in output_settings[section].items()
            if k not in ("clearing", "width", "banner_top", "banner_bottom")
        }


# Context history
context_history: DefaultDict[str, List[List[str]]] = defaultdict(list)
selected_history_index: Optional[int] = None

context_history_size = pwndbg.config.add_param(
    "context-history-size", 50, "number of context history entries to store"
)


@pwndbg.config.trigger(context_history_size)
def history_size_changed() -> None:
    if context_history_size <= 0:
        context_history.clear()
    else:
        for section in context_history:
            context_history[section] = context_history[section][-int(context_history_size) :]


def serve_context_history(function: Callable[P, List[str]]) -> Callable[P, List[str]]:
    @functools.wraps(function)
    def _serve_context_history(*a: P.args, **kw: P.kwargs) -> List[str]:
        global selected_history_index
        assert "context_" in function.__name__
        section_name = function.__name__.replace("context_", "")

        # If the history is disabled, just return the current output
        if context_history_size <= 0:
            return function(*a, **kw)

        # Add the current section to the history if it is not already there
        current_output = []
        if pwndbg.aglib.proc.alive:
            # Do not reevaluate the expressions section because its content is not deterministic.
            # Instead, reuse the last evaluated expression and rely on the other sections to deselect
            # the history entry if the output changed.
            # https://github.com/pwndbg/pwndbg/issues/2579
            if (
                section_name == "expressions"
                and selected_history_index is not None
                and len(context_history[section_name]) > 0
            ):
                current_output = context_history[section_name][-1]
            else:
                current_output = function(*a, **kw)
            if (
                len(context_history[section_name]) == 0
                or context_history[section_name][-1] != current_output
            ):
                context_history[section_name].append(current_output)
                selected_history_index = None
        # Show the history if the process is not running anymore
        elif context_history[section_name] and selected_history_index is None:
            selected_history_index = len(context_history[section_name]) - 1

        # Truncate the history to the configured size
        context_history[section_name] = context_history[section_name][-int(context_history_size) :]
        history = context_history[section_name]

        if selected_history_index is None:
            return current_output or function(*a, **kw)
        if not history or selected_history_index >= len(history):
            return []
        return history[selected_history_index]

    return _serve_context_history


def history_handle_unchanged_contents() -> None:
    if not context_history:
        return
    longest_history = max(len(h) for h in context_history.values())
    for section_name, history in context_history.items():
        # Duplicate the last entry if it is the same as the previous one
        # and wasn't added when the history was updated
        if len(history) == longest_history - 1:
            context_history[section_name].append(history[-1])
        # Prepend empty entries to the history to make all sections have the same length
        elif len(history) < longest_history - 1:
            context_history[section_name] = [
                [] for _ in range(longest_history - 1 - len(history))
            ] + history


parser = argparse.ArgumentParser(description="Select previous entry in context history.")
parser.add_argument(
    "count",
    type=int,
    nargs="?",
    default=1,
    help="The number of entries to go back in history",
)


@pwndbg.commands.Command(parser, aliases=["ctxp"], category=CommandCategory.CONTEXT)
def contextprev(count) -> None:
    global selected_history_index
    if not context_history:
        print(message.error("No context history captured"))
        return
    if selected_history_index is None:
        longest_history = max(len(h) for h in context_history.values())
        new_index = longest_history - count - 1
    else:
        new_index = selected_history_index - count
    selected_history_index = max(0, new_index)
    context()


parser = argparse.ArgumentParser(description="Select next entry in context history.")
parser.add_argument(
    "count",
    type=int,
    nargs="?",
    default=1,
    help="The number of entries to go forward in history",
)


@pwndbg.commands.Command(parser, aliases=["ctxn"], category=CommandCategory.CONTEXT)
def contextnext(count) -> None:
    global selected_history_index
    if not context_history:
        print(message.error("No context history captured"))
        return
    longest_history = max(len(h) for h in context_history.values())
    if selected_history_index is None:
        new_index = longest_history - 1
    else:
        new_index = selected_history_index + count
    selected_history_index = min(longest_history - 1, new_index)
    context()


parser = argparse.ArgumentParser(
    description="Search for a string in the context history and select that entry."
)
parser.add_argument(
    "needle",
    type=str,
    help="The string to search for in the context history",
)
parser.add_argument(
    "section",
    type=str,
    nargs="?",
    default=None,
    help="The section to search in. If not provided, search in all sections",
)


@pwndbg.commands.Command(parser, aliases=["ctxsearch"], category=CommandCategory.CONTEXT)
def contextsearch(needle, section) -> None:
    if not section:
        sections = context_history.keys()
    else:
        if section not in context_history:
            print(message.error(f"Section '{section}' not found in context history."))
            return
        sections = [section]

    matches: List[Tuple[str, int]] = []
    for section in sections:
        for i, entry in enumerate(context_history[section]):
            if not any(m[1] == i for m in matches) and any(needle in line for line in entry):
                matches.append((section, i))
    matches.sort(key=lambda m: m[1], reverse=True)

    if not matches:
        print(message.error(f"String '{needle}' not found in context history."))
        return

    # Select first match before currently selected entry
    global selected_history_index
    if selected_history_index is None:
        next_match = matches[0]
    else:
        for match in matches:
            if match[1] < selected_history_index:
                next_match = match
                break
        else:
            next_match = matches[0]
            print(message.warn("No more matches before the current entry. Starting from the top."))

    selected_history_index = next_match[1]
    print(
        message.info(
            f"Found {len(matches)} match{'es' if len(matches) > 1 else ''}. Selected entry {next_match[1] + 1} for match in section '{next_match[0]}'."
        )
    )
    context()


# Watches
expressions = []

parser = argparse.ArgumentParser(
    description="""
Adds an expression to be shown on context.

To remove an expression, see `cunwatch`.
""",
)
parser.add_argument(
    "cmd",
    type=str,
    default="eval",
    nargs="?",
    choices=("eval", "execute"),
    help="""Command to be used with the expression.
- eval: the expression is parsed and evaluated as in the debugged language.
- execute: the expression is executed as a GDB command.""",
)
parser.add_argument(
    "expression", type=str, help="The expression to be evaluated and shown in context"
)


@pwndbg.commands.Command(
    parser,
    aliases=["ctx-watch", "cwatch"],
    category=CommandCategory.CONTEXT,
    examples="""
For watching variables/expressions:
    cwatch BUF
    cwatch ITEMS[0]

For running commands:
    cwatch execute "ds BUF"
    cwatch execute "x/20x $rsp"
    cwatch execute "info args"
    """,
)
def contextwatch(expression, cmd) -> None:
    expressions.append((expression, cmd))


parser = argparse.ArgumentParser(
    description="Removes an expression previously added to be watched."
)
parser.add_argument("num", type=int, help="The expression number to be removed from context")


@pwndbg.commands.Command(
    parser, aliases=["ctx-unwatch", "cunwatch"], category=CommandCategory.CONTEXT
)
def contextunwatch(num) -> None:
    if num < 1 or num > len(expressions):
        print(message.error("Invalid input"))
        return

    expressions.pop(int(num) - 1)


@serve_context_history
def context_expressions(target=sys.stdout, with_banner=True, width=None):
    if not expressions:
        return []
    banner = [pwndbg.ui.banner("expressions", target=target, width=width)]
    output = []
    for i, (exp, cmd) in enumerate(expressions):
        header = f"{i + 1}: {C.highlight(exp)}"
        try:
            if cmd == "eval":
                value = str(gdb.parse_and_eval(exp))
            else:
                assert cmd == "execute"
                value = gdb.execute(exp, from_tty=False, to_string=True)
        except gdb.error as err:
            value = str(err)

        # When evaluating the expression we display it inline with the header, but when executing an
        # expression we display it on the next line
        if cmd == "eval":
            header += f" = {value}"
        output.append(header)

        if cmd == "execute":
            output.append(value)

    # gdb can output single elements with \n's
    # we split it up here so the cmd_line calculation is correct in context()
    _output = []
    for val in output:
        _output.extend(val.split("\n"))
    output = _output

    return banner + output if with_banner else output


config_context_ghidra = pwndbg.config.add_param(
    "context-ghidra",
    "never",
    "when to try to decompile the current function with ghidra",
    help_docstring="Doing this is slow and requires radare2/r2pipe or rizin/rzpipe.",
    param_class=pwndbg.lib.config.PARAM_ENUM,
    enum_sequence=["always", "never", "if-no-source"],
)


@serve_context_history
def context_ghidra(target=sys.stdout, with_banner=True, width=None):
    """
    Print out the source of the current function decompiled by ghidra.

    The context-ghidra config parameter is used to configure whether to always,
    never or only show the context if no source is available.
    """
    banner = (
        [pwndbg.ui.banner("ghidra decompile", target=target, width=width)] if with_banner else []
    )

    if config_context_ghidra == "never":
        return []

    if config_context_ghidra == "if-no-source":
        source_filename = pwndbg.gdblib.symbol.selected_frame_source_absolute_filename()
        if source_filename and os.path.exists(source_filename):
            return []

    try:
        return banner + pwndbg.ghidra.decompile().split("\n")
    except Exception as e:
        return banner + [message.error(e)]


parser = argparse.ArgumentParser(
    description="""
Print out the currently enabled context sections.

This is the text that gets printed on every stop. It can be useful
to run this command manually when you change some process/debugger
state but don't want to step/continue (e.g. after using the `down`
and `up` commands).
"""
)
parser.add_argument(
    "subcontext",
    nargs="*",
    type=str,
    default=None,
    help="Submenu to display: 'regs', 'disasm', 'code', 'stack', 'backtrace', 'ghidra', 'args', 'threads', 'heap_tracker', 'expressions', and/or 'last_signal'",
)
parser.add_argument(
    "--on",
    dest="enabled",
    action="store_true",
    default=None,
    help="Show the section(s) in subsequent context commands again. The section(s) have to be in the 'context-sections' list.",
)
parser.add_argument(
    "--off",
    dest="enabled",
    action="store_false",
    default=None,
    help="Do not show the section(s) in subsequent context commands even though they might be in the 'context-sections' list.",
)


@pwndbg.commands.Command(
    parser,
    aliases=["ctx"],
    category=CommandCategory.CONTEXT,
    notes="""
To see more commands related to context control run:
```
pwndbg -c context
```
To see context configuration run:
```
config context
```
""",
)
def context(subcontext=None, enabled=None) -> None:
    """
    Print out the current register, instruction, and stack context.

    Accepts subcommands 'reg', 'disasm', 'code', 'stack', 'backtrace', 'ghidra', 'args', 'threads', 'heap_tracker', 'expressions', and/or 'last_signal'.
    """
    # Allow to view history after the program has exited
    if not pwndbg.aglib.proc.alive and (context_history_size <= 0 or not context_history):
        log.error("context: The program is not being run.")
        return None

    if subcontext is None:
        subcontext = []
    args = subcontext

    if len(args) == 0:
        args = config_context_sections.split()

    sections = []
    if args:
        if selected_history_index is None:
            sections.append(("legend", lambda *args, **kwargs: [M.legend()]))
        else:
            longest_history = max(len(h) for h in context_history.values())
            history_status = f" (history {selected_history_index + 1}/{longest_history})"
            sections.append(("legend", lambda *args, **kwargs: [M.legend() + history_status]))

    sections += [(arg, context_sections.get(arg[0], None)) for arg in args]

    result = defaultdict(list)
    result_settings: DefaultDict[str, Dict[Any, Any]] = defaultdict(dict)
    for section, func in sections:
        if func:
            target = output(section)
            # Last section of an output decides about output settings
            settings = output_settings[section]
            if enabled is not None:
                settings["enabled"] = enabled
            if settings.get("enabled", True):
                result_settings[target].update(settings)
                with target as out:
                    result[target].extend(
                        func(
                            target=out,
                            width=settings.get("width", None),
                            with_banner=settings.get("banner_top", True),
                        )
                    )

    history_handle_unchanged_contents()

    for target, res in result.items():
        settings = result_settings[target]
        if len(res) > 0 and settings.get("banner_bottom", True):
            with target as out:
                res.append(pwndbg.ui.banner("", target=out, width=settings.get("width", None)))

    cmd_lines = 0
    for target, lines in result.items():
        with target as out:
            if result_settings[target].get("clearing", config_clear_screen) and lines:
                clear_screen(out)
            # The `if` here essentially checks whether the output is going to
            # the window where the debugger prompt is. The prompt is
            # always printed to stdout.
            if isinstance(target, StdOutput):
                # We always get a new line after the prompt, so the first line
                # doesn't need to have a "\n" in front. Furthermore, we need
                # to reserve a new line before the next prompt is printed.
                out.writelines(line + "\n" for line in lines)
            else:
                # A "\n" after the last line would just take up space in this case.
                # There will be a redundant preceding empty line when the first
                # context is printed, but it doesn't really matter.
                out.writelines("\n" + line for line in lines)
            out.flush()
        # Assuming the command window (where the prompt is printed) is always stdout
        if isinstance(target, StdOutput):
            assert all("\n" not in line for line in lines)
            cmd_lines += len(lines)

    reserve_lines_maybe(cmd_lines)


pwndbg.config.add_param(
    "show-compact-regs", False, "whether to show a compact register view with columns"
)
pwndbg.config.add_param(
    "show-compact-regs-columns", 2, "the number of columns (0 for dynamic number of columns)"
)
pwndbg.config.add_param("show-compact-regs-min-width", 20, "the minimum width of each column")
pwndbg.config.add_param(
    "show-compact-regs-separation", 4, "the number of spaces separating columns"
)


def calculate_padding_to_align(length, align):
    """Calculates the number of spaces to append to reach the next alignment.
    The next alignment point is given by "x * align >= length".
    """
    return 0 if length % align == 0 else (align - (length % align))


def compact_regs(regs, width=None, target=sys.stdout):
    columns = max(0, int(pwndbg.config.show_compact_regs_columns))
    min_width = max(1, int(pwndbg.config.show_compact_regs_min_width))
    separation = max(1, int(pwndbg.config.show_compact_regs_separation))

    if width is None:
        _height, width = pwndbg.ui.get_window_size(target)

    if columns > 0:
        # Adjust the minimum_width (column) according to the
        # layout depicted below, where there are "columns" columns
        # and "columns - 1" separations.
        #
        # |<----------------- window width -------------------->|
        # | column | sep. | column | sep. | ... | sep. | column |
        #
        # Which results in the following formula:
        # window_width = columns * min_width + (columns - 1) * separation
        # => min_width = (window_width - (columns - 1) * separation) / columns
        min_width = max(min_width, (width - (columns - 1) * separation) // columns)

    result = []

    line = ""
    line_length = 0
    for reg in regs:
        # Strip the color / hightlight information the get the raw text width of the register
        reg_length = len(pwndbg.color.strip(reg))

        # Length of line with unoccupied space and padding is required
        # to fit the register string onto the screen / display.
        line_length_with_padding = line_length
        line_length_with_padding += (
            separation if line_length != 0 else 0
        )  # No separation at the start of a line
        line_length_with_padding += calculate_padding_to_align(
            line_length_with_padding, min_width + separation
        )

        # When element does not fully fit, then start a new line
        if line_length_with_padding + max(reg_length, min_width) > width:
            result.append(line)

            line = ""
            line_length = 0
            line_length_with_padding = 0

        # Add padding in front of the next printed register
        if line_length != 0:
            line += " " * (line_length_with_padding - line_length)

        line += reg
        line_length = line_length_with_padding + reg_length

    # Append last line if required
    if line_length != 0:
        result.append(line)

    return result


@serve_context_history
def context_regs(target=sys.stdout, with_banner=True, width=None):
    regs = get_regs()
    if pwndbg.config.show_compact_regs:
        regs = compact_regs(regs, target=target, width=width)

    info = " / show-flags {} / show-compact-regs {}".format(
        "on" if pwndbg.config.show_flags else "off",
        "on" if pwndbg.config.show_compact_regs else "off",
    )
    banner = [pwndbg.ui.banner("registers", target=target, width=width, extra=info)]
    return banner + regs if with_banner else regs


@serve_context_history
def context_heap_tracker(target=sys.stdout, with_banner=True, width=None):
    if not pwndbg.gdblib.ptmalloc2_tracking.is_enabled():
        return []

    banner = [pwndbg.ui.banner("heap tracker", target=target, width=width, extra="")]

    if pwndbg.gdblib.ptmalloc2_tracking.last_issue is not None:
        info = [
            f"Detected the following potential issue: {pwndbg.gdblib.ptmalloc2_tracking.last_issue}"
        ]
        pwndbg.gdblib.ptmalloc2_tracking.last_issue = None
    else:
        info = ["Nothing to report."]

    return banner + info if with_banner else info


parser = argparse.ArgumentParser(description="Print out all registers and enhance the information.")
parser.add_argument("regs", nargs="*", type=str, default=None, help="Registers to be shown")


@pwndbg.commands.Command(parser, category=CommandCategory.CONTEXT)
@pwndbg.commands.OnlyWhenRunning
def regs(regs=[]) -> None:
    """Print out all registers and enhance the information."""
    print("\n".join(get_regs(regs)))


pwndbg.config.add_param("show-flags", False, "whether to show flags registers")
pwndbg.config.add_param("show-retaddr-reg", True, "whether to show return address register")


class RegisterContext:
    changed: List[str]

    def __init__(self):
        self.changed = pwndbg.aglib.regs.changed

    def get_prefix(self, reg):
        # Make the register stand out and give a color if changed
        regname = C.register(reg.ljust(4).upper())
        if reg in self.changed:
            regname = C.register_changed(regname)

        # Show a marker next to the register if it changed
        change_marker = f"{C.config_register_changed_marker}"
        m = (
            " " * len(change_marker)
            if reg not in self.changed
            else C.register_changed(change_marker)
        )
        return f"{m}{regname}"

    def get_register_value(self, reg):
        val = pwndbg.aglib.regs.read_reg(reg)
        if val is None:
            print(message.warn(f"Unknown register: {reg!r}"))
            return None
        return val

    def flag_register_context(self, reg, bit_flags):
        val = self.get_register_value(reg)
        if val is None:
            return None
        desc = C.format_flags(val, bit_flags, pwndbg.aglib.regs.last.get(reg, 0))
        prefix = self.get_prefix(reg)
        return f"{prefix} {desc}"

    def segment_registers_context(self, regs):
        result = ""
        for reg in regs:
            val = self.get_register_value(reg)
            if val is None:
                continue
            prefix = self.get_prefix(reg)
            result += f"{prefix} {hex(val)}   "
        return result

    def addressing_register_context(self, reg, is_virtual):
        if is_virtual:
            return self.register_context_default(reg)
        val = self.get_register_value(reg)
        if val is None:
            return None
        prefix = self.get_prefix(reg)
        desc = hex(val)
        if pwndbg.aglib.kernel.has_debug_symbols():
            try:
                virtual = pwndbg.aglib.kernel.phys_to_virt(val)
                desc += f" [virtual: {pwndbg.chain.format(virtual)}]"
            except Exception:
                pass
        return f"{prefix} {desc}"

    def register_context_default(self, reg):
        val = self.get_register_value(reg)
        if val is None:
            return None
        desc = ""
        desc = pwndbg.chain.format(val)
        prefix = self.get_prefix(reg)
        return f"{prefix} {desc}"


def get_regs(regs: List[str] = None):
    regs: List[Any] = regs
    result = []
    rc = RegisterContext()

    if regs is None:
        regs = []

    if len(regs) == 0:
        regs += pwndbg.aglib.regs.gpr

        regs.append(pwndbg.aglib.regs.frame)
        regs.append(pwndbg.aglib.regs.stack)

        if pwndbg.config.show_retaddr_reg:
            regs += pwndbg.aglib.regs.retaddr

        regs.append(pwndbg.aglib.regs.current.pc)

        if pwndbg.aglib.qemu.is_qemu_kernel() and pwndbg.aglib.regs.kernel is not None:
            controls = pwndbg.aglib.regs.kernel.controls
            if controls is not None:
                for regname, control in controls.items():
                    control.update(regname)
                    regs.append(control)
            msrs = pwndbg.aglib.regs.kernel.msrs
            if msrs is not None:
                for regname, msr in msrs.items():
                    msr.update(regname)
                    regs.append(msr)
        if pwndbg.config.show_flags:
            flags = pwndbg.aglib.regs.flags
            if flags is not None:
                for regname, flag in flags.items():
                    flag.update(regname)
                    regs.append(flag)
        if pwndbg.aglib.qemu.is_qemu_kernel() and pwndbg.aglib.regs.kernel is not None:
            if pwndbg.aglib.regs.kernel.segments is not None:
                regs.append(pwndbg.aglib.regs.kernel.segments)

    for reg in regs:
        if reg is None:
            continue
        if not isinstance(reg, str):
            desc = reg.context(rc)
            if desc is not None:
                result.append(desc)
                continue
        desc = rc.register_context_default(reg)
        if desc is not None:
            result.append(desc)

    return result


disasm_lines = pwndbg.config.add_param(
    "context-disasm-lines", 10, "number of additional lines to print in the disasm context"
)


def try_emulate_if_bug_disable(handler: Callable[[], T]) -> T:
    try:
        return handler()
    except U.UcError as e:
        print(
            message.warn(
                f"Warning: Emulation context disabled due to a Unicorn error: \n{str(e)}\n"
                "If you want to enable it again, use `set emulate on`."
            )
        )
        pwndbg.config.emulate.value = "off"
        return handler()


@serve_context_history
def context_disasm(target=sys.stdout, with_banner=True, width=None):
    flavor = pwndbg.dbg.x86_disassembly_flavor()
    syntax = pwndbg.aglib.disasm.disassembly.CapstoneSyntax[flavor]

    # Get the Capstone object to set disassembly syntax
    cs = next(iter(pwndbg.aglib.disasm.disassembly.get_disassembler.cache.values()), None)

    # The `None` case happens when the cache was not filled yet (see e.g. #881)
    if cs is not None and cs.syntax != syntax:
        pwndbg.lib.cache.clear_caches()
        pwndbg.aglib.disasm.disassembly.computed_instruction_cache.clear()

    result = try_emulate_if_bug_disable(
        lambda: pwndbg.aglib.nearpc.nearpc(
            back_lines=disasm_lines // 2,
            total_lines=int(disasm_lines) + 1,
            emulate=bool(not pwndbg.config.emulate == "off"),
            use_cache=True,
        )
    )

    # Note: we must fetch emulate value again after disasm since
    # we check if we can actually use emulation in `can_run_first_emulate`
    # and this call may disable it
    thumb_mode_str = get_thumb_mode_string()
    if thumb_mode_str is not None:
        info = " / {} / {} mode / set emulate {}".format(
            pwndbg.aglib.arch.name, thumb_mode_str, pwndbg.config.emulate
        )
    else:
        info = " / {} / set emulate {}".format(pwndbg.aglib.arch.name, pwndbg.config.emulate)
    banner = [pwndbg.ui.banner("disasm", target=target, width=width, extra=info)]

    # If we didn't disassemble backward, try to make sure
    # that the amount of screen space taken is roughly constant.
    while len(result) < disasm_lines + 1:
        result.append("")

    return banner + result if with_banner else result


theme.add_param("highlight-source", True, "whether to highlight the closest source line")
source_disasm_lines = pwndbg.config.add_param(
    "context-code-lines", 10, "number of source code lines to print by the context command"
)
pwndbg.config.add_param(
    "context-code-tabstop", 8, "number of spaces that a <tab> in the source code counts for"
)
theme.add_param("code-prefix", "►", "prefix marker for 'context code' command")


@pwndbg.lib.cache.cache_until("start")
def get_highlight_source(filename: str) -> Tuple[str, ...]:
    # Notice that the code is cached
    with open(filename, encoding="utf-8", errors="ignore") as f:
        source = f.read()

    if pwndbg.config.syntax_highlight:
        source = H.syntax_highlight(source, filename)

    source_lines = source.split("\n")
    source_lines = tuple(line.rstrip() for line in source_lines)
    return source_lines


def get_filename_and_formatted_source():
    """
    Returns formatted, lines limited and highlighted source as list
    or if it isn't there - an empty list
    """
    sal = pwndbg.dbg.selected_frame().sal()

    # Check if source code is available
    if sal is None:
        return "", [], 0

    # Get the full source code
    filename, closest_line = sal

    try:
        source = get_highlight_source(filename)
    except OSError:
        return "", [], closest_line

    if not source:
        return "", [], closest_line

    n = int(source_disasm_lines)

    # Compute the line range
    start = max(closest_line - 1 - n // 2, 0)
    end = min(closest_line - 1 + n // 2 + 1, len(source))
    num_width = len(str(end))

    # split the code
    source = source[start:end]

    # Compute the prefix_sign length
    prefix_sign = C.prefix(str(pwndbg.config.code_prefix))
    prefix_width = len(prefix_sign)

    # Format the output
    formatted_source = []
    for line_number, code in enumerate(source, start=start + 1):
        if pwndbg.config.context_code_tabstop > 0:
            code = code.replace("\t", " " * pwndbg.config.context_code_tabstop)
        fmt = " {prefix_sign:{prefix_width}} {line_number:>{num_width}} {code}"
        if pwndbg.config.highlight_source and line_number == closest_line:
            fmt = C.highlight(fmt)

        line = fmt.format(
            prefix_sign=prefix_sign if line_number == closest_line else "",
            prefix_width=prefix_width,
            line_number=line_number,
            num_width=num_width,
            code=code,
        )
        formatted_source.append(line)

    return filename, formatted_source, closest_line


should_decompile = pwndbg.config.add_param(
    "context-integration-decompile",
    True,
    "whether context should fall back to decompilation with no source code",
)


@serve_context_history
def context_code(target=sys.stdout, with_banner=True, width=None):
    filename, formatted_source, line = get_filename_and_formatted_source()

    # Try getting source from files
    if formatted_source:
        bannerline = (
            [pwndbg.ui.banner("Source (code)", target=target, width=width)] if with_banner else []
        )
        return bannerline + [f"In file: {filename}:{line}"] + formatted_source

    if should_decompile:
        # Will be None if decompilation fails
        code = pwndbg.integration.provider.decompile(pwndbg.aglib.regs.pc, int(source_disasm_lines))

        if code:
            bannerline = (
                [pwndbg.ui.banner("Decomp", target=target, width=width)] if with_banner else []
            )
            return bannerline + code
        else:
            return []


stack_lines = pwndbg.config.add_param(
    "context-stack-lines", 8, "number of lines to print in the stack context"
)


@serve_context_history
def context_stack(target=sys.stdout, with_banner=True, width=None):
    result = [pwndbg.ui.banner("stack", target=target, width=width)] if with_banner else []
    telescope = pwndbg.commands.telescope.telescope(
        pwndbg.aglib.regs.sp, to_string=True, count=stack_lines
    )
    if telescope:
        result.extend(telescope)
    return result


backtrace_lines = pwndbg.config.add_param(
    "context-backtrace-lines", 8, "number of lines to print in the backtrace context"
)
backtrace_frame_label = theme.add_param(
    "backtrace-frame-label", "", "frame number label for backtrace"
)


@serve_context_history
def context_backtrace(with_banner=True, target=sys.stdout, width=None):
    result = []

    if with_banner:
        result.append(pwndbg.ui.banner("backtrace", target=target, width=width))

    this_frame = pwndbg.dbg.selected_frame()
    newest_frame = this_frame
    oldest_frame = this_frame

    for i in range(backtrace_lines - 1):
        try:
            candidate = oldest_frame.parent()
        # We catch an error in case of a `gdb.error: PC not saved` case
        except pwndbg.dbg_mod.Error:
            break

        if not candidate:
            break
        oldest_frame = candidate

    for i in range(backtrace_lines - 1):
        candidate = newest_frame.child()
        if not candidate:
            break
        newest_frame = candidate

    frame = newest_frame
    i = 0
    bt_prefix = f"{pwndbg.config.backtrace_prefix}"
    while True:
        prefix = bt_prefix if frame == this_frame else " " * len(bt_prefix)
        prefix = f" {c.prefix(prefix)}"
        addrsz = c.address(pwndbg.ui.addrsz(frame.pc()))
        symbol = c.symbol(pwndbg.aglib.symbol.resolve_addr(int(frame.pc())))
        if symbol:
            addrsz = f"{addrsz} {symbol}"
        result.append(f"{prefix} {c.frame_label(f'{backtrace_frame_label}{i}')} {addrsz}")

        if frame == oldest_frame:
            break

        frame = frame.parent()
        i += 1
    return result


@serve_context_history
def context_args(with_banner=True, target=sys.stdout, width=None):
    args = pwndbg.arguments.format_args(pwndbg.aglib.disasm.disassembly.one())

    # early exit to skip section if no arg found
    if not args:
        return []

    if with_banner:
        args.insert(0, pwndbg.ui.banner("arguments", target=target, width=width))

    return args


last_signal: List[str] = []

thread_status_messages = {
    "running": pwndbg.color.light_green("running"),
    "stopped": pwndbg.color.yellow("stopped"),
    "exited": pwndbg.color.gray("exited "),
}


def get_thread_status(thread):
    if thread.is_running():
        return thread_status_messages["running"]
    elif thread.is_stopped():
        return thread_status_messages["stopped"]
    elif thread.is_exited():
        return thread_status_messages["exited"]
    else:
        return "unknown"


@serve_context_history
def context_threads(with_banner=True, target=sys.stdout, width=None):
    try:
        original_thread = gdb.selected_thread()
    except SystemError:
        original_thread = None
    try:
        original_frame = gdb.selected_frame()
    except gdb.error:
        original_frame = None

    all_threads = gdb.selected_inferior().threads()[::-1]

    displayed_threads = []

    if original_thread is not None and original_thread.is_valid():
        displayed_threads.append(original_thread)

    for thread in all_threads:
        if len(displayed_threads) >= int(config_max_threads_display):
            break

        if thread.is_valid() and thread is not original_thread:
            displayed_threads.append(thread)

    num_threads_not_shown = len(all_threads) - len(displayed_threads)

    if len(displayed_threads) < 2:
        return []

    out = (
        [pwndbg.ui.banner(f"threads ({len(all_threads)} total)", target=target, width=width)]
        if with_banner
        else []
    )
    max_name_length = 0
    max_global_num_len = 0

    for thread in displayed_threads:
        name = thread.name or ""
        if len(name) > max_name_length:
            max_name_length = len(name)
        if len(str(thread.global_num)) > max_global_num_len:
            max_global_num_len = len(str(thread.global_num))

    for thread in filter(lambda t: t.is_valid(), displayed_threads):
        selected = " ►" if thread is original_thread else "  "
        name = thread.name if thread.name is not None else ""
        name_padding = max_name_length - len(name)
        global_num_padding = max(2, max_global_num_len - len(str(thread.global_num)))
        status = get_thread_status(thread)

        line = (
            f" {selected} {thread.global_num} "
            f"{' ' * global_num_padding}"
            f'"{pwndbg.color.cyan(name)}" '
            f'{" " * name_padding}'
            f"{status}: "
        )

        if thread.is_stopped():
            thread.switch()
            pc = gdb.selected_frame().pc()

            pc_colored = M.get(pc)
            symbol = pwndbg.aglib.symbol.resolve_addr(int(pc))

            line += f"{pc_colored}"
            if symbol:
                line += f" <{pwndbg.color.bold(pwndbg.color.green(symbol))}> "

        out.append(line)

    if num_threads_not_shown:
        out.append(
            pwndbg.lib.tips.color_tip(
                f"Not showing {num_threads_not_shown} thread(s). Use `set context-max-threads <number of threads>` to change this."
            )
        )

    if original_thread is not None and original_thread.is_valid():
        original_thread.switch()
    if original_frame is not None and original_frame.is_valid():
        original_frame.select()

    return out


def save_signal(signal) -> None:
    global last_signal
    last_signal = result = []

    if isinstance(signal, gdb.ExitedEvent):
        # Booooo old gdb
        if hasattr(signal, "exit_code"):
            result.append(message.exit(f"Exited: {signal.exit_code}"))

    elif isinstance(signal, gdb.SignalEvent):
        msg = f"Program received signal {signal.stop_signal}"

        if signal.stop_signal == "SIGSEGV":
            # When users use rr (https://rr-project.org or https://github.com/mozilla/rr)
            # we can't access $_siginfo, so lets just show current pc
            # see also issue 476
            if _is_rr_present():
                msg += f" (current pc: {pwndbg.aglib.regs.pc:#x})"
            else:
                try:
                    si_addr = gdb.parse_and_eval("$_siginfo._sifields._sigfault.si_addr")
                    msg += f" (fault address {int(si_addr):#x})"
                except gdb.error:
                    pass
        result.append(message.signal(msg))

    elif isinstance(signal, gdb.BreakpointEvent):
        for bkpt in signal.breakpoints:
            result.append(message.breakpoint(f"Breakpoint {(bkpt.location)}"))


if pwndbg.dbg.is_gdblib_available():
    gdb.events.cont.connect(save_signal)
    gdb.events.stop.connect(save_signal)
    gdb.events.exited.connect(save_signal)


@serve_context_history
def context_last_signal(with_banner=True, target=sys.stdout, width=None):
    if not last_signal:
        return []

    result = last_signal[::]
    if with_banner:
        result.insert(0, pwndbg.ui.banner("last signal", target=target, width=width))

    return result


context_sections = {
    "a": context_args,
    "r": context_regs,
    "d": context_disasm,
    "s": context_stack,
    "b": context_backtrace,
    "c": context_code,
}


if pwndbg.dbg.is_gdblib_available():
    # Add the sections that need gdblib.
    context_sections = {
        **context_sections,
        "e": context_expressions,
        "g": context_ghidra,
        "h": context_heap_tracker,
        "t": context_threads,
        "l": context_last_signal,
    }


@pwndbg.lib.cache.cache_until("forever")
def _is_rr_present() -> bool:
    """
    Checks whether rr project is present (so someone launched e.g. `rr replay <some-recording>`)
    """

    # this is ugly but I couldn't find a better way to do it
    # feel free to refactor it
    globals_list_literal_str = gdb.execute("python print(list(globals().keys()))", to_string=True)
    interpreter_globals = ast.literal_eval(globals_list_literal_str)

    return "RRCmd" in interpreter_globals and "RRWhere" in interpreter_globals
